Many industrial tasks require the use of hand-held tools such as pliers, cutters and the like. While these tools are not necessarily large in themselves, the continued use and hand manipulation of these tools in the performance of repetitive motions and tasks can result in fatigue and/or stress to the operator's hand and/or wrist which can lead to a condition referred to as a condition referred to as Cumulative Trauma Disorder ("CTD").
In addressing this problem, a number of factors have to be considered. One factor, of course, is the provision of a construction having a desired mechanical advantage so as to maintain the forces necessary for squeezing or cutting objects to a reasonable level; equally important, however, is a construction providing a generally uniform configuration facilitating gripping by the hand and allowing the gripping pressure to be distributed over the full palm area while permitting an even application of force from all four fingers.
Another factor is the provision of a handle contour which facilitates gripping while still providing an effective shape especially suited to the hand.
Another factor is the provision of a handle construction and design which is sufficiently flexible while still providing adequate strength to withstand the necessary work loads without permanent deformation or breakage. This flexibility acts to absorb the shock loads which would normally be directed to the palms, fingers and wrist when cutting or squeezing various objects.
Yet, another factor is a construction meeting the above objectives while still providing a hand tool which is compact and of a generally light weight.
The above objectives are met in the unique design of the present invention. Here a basic hand tool body is provided with a nose portion comprising conventional cutting blades and/or gripping members which are pivotally connected through handles. This basic structure is constructed of a strong, durable metal which commonly is a high strength ferrous material. The handles can define the typically arcuately bowed shape. In the present invention, however, the handles are elongated by use of extension members made of a flexible plastic material. The extension members are adapted to provide a preselected extension and contour designed to complement the existing handle shape. This will provide an overall, unified shape which comfortably fits the operator's hand; at the same time an increase in mechanical advantage is realized from the increase in handle length. The extension members are generally of a minimum cross-section and hence minimum weight. Next, a generally soft, pliable plastic sheath is placed over each of the extension members. The sheath follows the combined contour of the original handle and associated extension member and hence maintains the desired contour. More importantly, however, the sheath being generally pliable will readily enhance the cushion effect of the handle assembly.
Therefore, it is an object of the present invention to provide a handle assembly for hand-held tools such as pliers, cutters and the like which is of a unique construction for minimizing operator stress and fatigue.
It is still another object of the present invention to provide a unique handle assembly of the above noted type which is of a lightweight construction.
It is a general object to provide a hand-held tool such as that described above having a uniquely constructed handle assembly.
Additional objects, advantages, and features of the present invention will become apparent from the following description and appended claims taken in conjunction with the accompanying drawings.